<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .main {
            width: 300px;
            height: 300px;
            display: grid;
            grid-template-columns: 1fr 1fr 1fr;
            grid-template-rows: 1fr 1fr 1fr;
            background-color: #f9f9f9;
            border: 1px solid red;
        }

        .main div:nth-of-type(1) {
            box-sizing: border-box;
            background-color: pink;
            grid-column-start: 2;
            grid-column-end: 2;
        }
    </style>
</head>
<body>
<div class="main">
    <div>1</div>
</div>
</body>
</html>
